G.J. de Bruijnhttp://repub.eur.nl/ppl/3625/
List of Publicationsenhttp://repub.eur.nl/eur_signature.pnghttp://repub.eur.nl/
RePub, Erasmus University RepositorySaturated fat consumption and the Theory of Planned Behaviour: Exploring additive and interactive effects of habit strengthhttp://repub.eur.nl/pub/29364/
Mon, 01 Sep 2008 00:00:01 GMT<div>G.J. de Bruijn</div><div>W. Kroeze</div><div>A. Oenema</div><div>J. Brug</div>
The additive and interactive effects of habit strength in the explanation of saturated fat intake were explored within the framework of the Theory of Planned Behaviour (TPB). Cross-sectional data were gathered in a Dutch adult sample (n = 764) using self-administered questionnaires and analyzed using hierarchical regression analyses and simple slope analyses. Results showed that habit strength was a significant correlate of fat intake (β = -0.11) and significantly increased the amount of explained variance in fat intake (R2-change= 0.01). Furthermore, based on a significant interaction effect (β = 0.11), simple slope analyses revealed that intention was a significant correlate of fat intake for low levels (β = -0.29) and medium levels (β = -0.19) of habit strength, but a weaker and non-significant correlate for high levels (β = -0.07) of habit strength. Higher habit strength may thus make limiting fat intake a non-intentional behaviour. Implications for information and motivation-based interventions are discussed. Does habit strength moderate the intention-behaviour relationship in the Theory of Planned Behaviour? the case of fruit consumptionhttp://repub.eur.nl/pub/36231/
Sat, 01 Dec 2007 00:00:01 GMT<div>G.J. de Bruijn</div><div>S.P. Kremers</div><div>E. Vet</div><div>J. de Nooijer</div><div>W. van Mechelen</div><div>J. Brug</div>
The present study examined if habit strength moderated the influence of intention on fruit consumption in a Dutch adult sample (N = 521, 46.3% males, mean age = 34.50, SD = 10.87), using the theoretical relations of the Theory of Planned Behaviour (TPB). TPB variables and habit strength were assessed at baseline. Fruit consumption was assessed with a validated questionnaire five weeks later. Three groups were created: low habit strength (n = 180), medium habit strength (n = 185) and high habit strength (n = 156). Confirmatory factor analyses and multi-group path analyses were performed using AMOS 4.0. A good fit was obtained for the overall measurement model and the structural models. Multi-group path analyses showed that intention was a significant predictor of fruit consumption in the low habit ( = 0.36, p 0.001) and medium habit group ( = 0.30, p 0.001), but a non-significant predictor in the high habit group ( = 0.05, p = 0.596). Implications for information-based and motivation-based interventions are discussed.Associations of social-environmental and individual-level factors with adolescent soft drink consumption: Results from the SMILE studyhttp://repub.eur.nl/pub/35957/
Sun, 01 Apr 2007 00:00:01 GMT<div>G.J. de Bruijn</div><div>S.P. Kremers</div><div>H. de Vries</div><div>W. van Mechelen</div><div>J. Brug</div>
Adolescent obesity is positively associated with soft drink consumption. We investigated the association of social-environmental and individual-level factors with soft drink consumption in a Dutch adolescent sample. Data were gathered in a longitudinal Dutch adolescent sample (n = 208, 62% girls). Soft drink consumption, social cognitions from the Theory of Planned Behaviour and parenting practices towards limited soft drink intake, and Big Five personality dimensions were assessed. Data were analyzed using three-step linear regression analyses. Effect sizes were used as the informational source for the explanatory value of the model. Interaction terms were computed to test the individual-environment interaction. Attitude and subjective norm were significantly associated with soft drink consumption. When controlling for social cognitions, the distal variables parenting practices and the personality dimension Agreeableness remained significantly associated with soft drink consumption. Agreeableness moderated the association of parenting practices with adolescent soft drink consumption. Standardized regression coefficients ranged from 0.16 to 0.24 and explained 14% of the variance in soft drink consumption, indicating a medium effect size. Stricter parenting practices were associated with less soft drink consumption and these effects were moderated by adolescent personality. The direct effects of practices and personality are noteworthy from a theoretical perspective. Implications for obesity prevention interventions are discussed. Moderators of Environmental Intervention Effects on Diet and Activity in Youthhttp://repub.eur.nl/pub/36222/
Thu, 01 Feb 2007 00:00:01 GMT<div>S.P. Kremers</div><div>G.J. de Bruijn</div><div>M. Droomers</div><div>F.J. van Lenthe</div><div>J. Brug</div>
Background: The complexity of the relationship between environmental factors on the one hand and dietary behavior and physical activity on the other necessitates the search for moderators of environmental influences. The current evidence base is reviewed regarding potential moderating factors in the effectiveness of environmental interventions aimed at diet and/or physical activity of children and adolescents. Methods: The following databases were used: (1) Medline, (2) PubMed, (3) PsychInfo, (4) Web of Science, and (5) ERIC. Additionally, all potentially relevant references in recent reviews were checked. Results: Of the 41 studies included in the review, only seven studies (17%) were identified that reported tests of potential moderators of intervention effects. Gender proved to be the most frequently studied potential moderator. Additionally, race, age, and site have been studied regarding their potential role in modifying the effect of environmental interventions. Discussion: The small number of studies identified in this review prohibited us from attempting to formulate a conclusion on differential environment-behavior relationships in distinct subgroups. Rather than being an exception, it is argued that tests of effect modifiers should become common practice in behavioral nutrition and physical activity research to increase our understanding of mechanisms of behavior change and to optimize interventions. Environmental determinants of fruit and vegetable consumption among adults: A systematic reviewhttp://repub.eur.nl/pub/63605/
Sun, 01 Oct 2006 00:00:01 GMT<div>C.B.M. Kamphuis</div><div>K. Giskes</div><div>G.J. de Bruijn</div><div>W. Wendel-Vos</div><div>J. Brug</div><div>F.J. van Lenthe</div>
The current ecological approach in health behaviour research recognises that health behaviour needs to be understood in a broad environmental context. This has led to an exponential increase in the number of studies on this topic. It is the aim of this systematic review to summarise the existing empirical evidence pertaining to environmental influences on fruit and vegetable (FV) consumption. The environment was defined as 'all factors external to the individual'. Scientific databases and reference lists of selected papers were systematically searched for observational studies among adults (18-60 years old), published in English between 1 January 1980 and 31 December 2004, with environmental factor(s) as independent factor(s), and fruit intake, vegetable intake or FV intake combined as one outcome measure as dependent factor(s). Findings showed there was a great diversity in the environmental factors studied, but that the number of replicated studies for each determinant was limited. Most evidence was found for household income, as people with lower household incomes consistently had a lower FV consumption. Married people had higher intakes than those who were single, whereas having children showed mixed results. Good local availability (e.g. access to one's own vegetable garden, having low food insecurity) seemed to exert a positive influence on intake. Regarding the development of interventions, improved opportunities for sufficient FV consumption among low-income households are likely to lead to improved intakes. For all other environmental factors, more replicated studies are required to examine their influence on FV intake.Modeling Individual and Physical Environmental Factors with Adolescent Physical Activityhttp://repub.eur.nl/pub/56613/
Thu, 01 Jun 2006 00:00:01 GMT<div>G.J. de Bruijn</div><div>S.P. Kremers</div><div>G. Lensvelt-Mulders</div><div>H. de Vries</div><div>W. van Mechelen</div><div>J. Brug</div>
Background: Recent calls have been made to consider both environmental factors and individual-level factors in the explanation of physical activity (PA). The present study tested a conceptual model that integrated past PA, relevant environmental-level and individual-level factors and their associations with adolescent PA, using the tenets of the Theory of Planned Behavior (TPB). Methods: Data were gathered in an adolescent sample (n=221; 60% girls) using questionnaires. PA was assessed in May 2003 and November 2003. Theory of Planned Behavior cognitions regarding PA and the environmental factors under study were assessed in November 2003. Confirmatory factor analyses and path analyses were performed using AMOS software. Results: The initial structural model did not provide an acceptable fit to the data. Including a direct path from past PA to current PA significantly improved model fit to an acceptable fit. Including a direct path from past PA to environmental perceptions did not significantly improve model fit. Including a direct path from the environmental variables to current PA did not significantly improve model fit. Current PA was most strongly influenced by past PA, while environmental aesthetics and distance to PA opportunities were indirectly related to adolescents' intention to be physically active. Significant standardized path coefficients ranged from 0.14 to 0.34 and explained 17% variance in current PA. Conclusions: Combining past PA, Theory of Planned Behavior cognitions, and environmental factors increased our understanding of their relative influences on adolescent PA. Implications for future research on physical activity are discussed.Environmental influences on energy balance-related behaviors: A dual-process viewhttp://repub.eur.nl/pub/68125/
Mon, 15 May 2006 00:00:01 GMT<div>S.P. Kremers</div><div>G.J. de Bruijn</div><div>T.L.S. Visscher</div><div>W. van Mechelen</div><div>N.K. de Vries</div><div>J. Brug</div>
Background: Studies on the impact of the 'obesogenic' environment have often used non-theoretical approaches. In this journal's debate and in other papers authors have argued the necessity of formulating conceptual models for differentiating the causal role of environmental influences on behavior. Discussion: The present paper aims to contribute to the debate by presenting a dual-process view on the environment - behavior relationship. This view is conceptualized in the EnRG framework (Environmental Research framework for weight Gain prevention). In the framework, behavior is postulated to be the result of a simultaneous influence of conscious and unconscious processes. Environmental influences are hypothesized to influence behavior both indirectly and directly. The indirect causal mechanism reflects the mediating role of behavior-specific cognitions in the influence of the environment on behavior. A direct influence reflects the automatic, unconscious, influence of the environment on behavior. Specific personal and behavioral factors are postulated to moderate the causal path (i.e., inducing either the automatic or the cognitively mediated environment - behavior relation). In addition, the EnRG framework applies an energy balance-approach, stimulating the integrated study of determinants of diet and physical activity. Conclusion: The application of a dual-process view may guide research towards causal mechanisms linking specific environmental features with energy balance-related behaviors in distinct populations. The present paper is hoped to contribute to the evolution of a paradigm that may help to disentangle the role of 'obesogenic' environmental factors.Environmental determinants of fruit and vegetable consumption among adults: a systematic reviewhttp://repub.eur.nl/pub/8914/
Sun, 01 Jan 2006 00:00:01 GMT<div>C.B.M. Kamphuis</div><div>K. Giskes</div><div>G.C.W. Wendel-Vos</div><div>G.J. de Bruijn</div><div>J. Brug</div><div>F.J. van Lenthe</div>
The current ecological approach in health behaviour research recognises that health behaviour needs to be understood in a broad environmental
context. This has led to an exponential increase in the number of studies on this topic. It is the aim of this systematic review to summarise the
existing empirical evidence pertaining to environmental influences on fruit and vegetable (FV) consumption. The environment was defined as ‘all
factors external to the individual’. Scientific databases and reference lists of selected papers were systematically searched for observational studies
among adults (18–60 years old), published in English between 1 January 1980 and 31 December 2004, with environmental factor(s) as independent factor(s), and fruit intake, vegetable intake or FV intake combined as one outcome measure as dependent factor(s). Findings showed there was
a great diversity in the environmental factors studied, but that the number of replicated studies for each determinant was limited. Most evidence
was found for household income, as people with lower household incomes consistently had a lower FV consumption. Married people had higher
intakes than those who were single, whereas having children showed mixed results. Good local availability (e.g. access to one’s own vegetable
garden, having low food insecurity) seemed to exert a positive influence on intake. Regarding the development of interventions, improved opportunities for sufficient FV consumption among low-income households are likely to lead to improved intakes. For all other environmental factors,
more replicated studies are required to examine their influence on FV intake.Is personality related to fruit and vegetable intake and physical activity in adolescents?http://repub.eur.nl/pub/54367/
Thu, 01 Dec 2005 00:00:01 GMT<div>G.J. de Bruijn</div><div>S.P. Kremers</div><div>W. van Mechelen</div><div>J. Brug</div>
Personality is regarded as a distal determinant of health behavior and has been found to be associated with health behavior in young adults. Research investigating the association between personality and health behaviors in adolescents, however, is lacking. The present study explored the direct associations between Big Five personality dimensions with fruit and vegetable consumption and physical activity (PA) in two Dutch adolescent samples [Sample 1: n = 504; mean age = 14.5 years (SD = 1.7); response rate 20%; Sample 2: n = 476; mean age = 14.9 (SD = 2.0); response rate 17%]. Behavioral outcomes and personality were assessed with validated self-administered questionnaires. Bivariate correlations and multiple regression analyses were conducted, and Cohen's effect sizes were used to interpret the associations found. Agreeableness was positively associated with vegetable consumption, while Openness to Experience was positively associated with fruit consumption and vegetable consumption. Extraversion was positively associated with sports-related PA. Standardized regression coefficients for personality dimensions ranged from 0.09 to 0.13, explaining 3-6% of variance in behavior, indicating small effect sizes. Our results suggest that personality dimensions are associated with fruit and vegetable consumption and sports-related PA in adolescents. Future research should explore possible mediators between personality and health behavior in adolescents.Determinants of adolescent bicycle use for transportation and snacking behaviorhttp://repub.eur.nl/pub/74456/
Wed, 01 Jun 2005 00:00:01 GMT<div>G.J. de Bruijn</div><div>S.P. Kremers</div><div>H.P. Schaalma</div><div>W. van Mechelen</div><div>J. Brug</div>
Background. The prevalence of obesity has reached epidemic proportions in many countries and is largely due to behavioral factors that disrupt the energy balance. The purpose of the study was to test how well our conceptual model, combining features from the Theory of Planned Behavior and the Theory of Triadic Influence, explained two behaviors related to the energy balance, namely bicycle use for transportation and snacking behavior in a Dutch adolescent sample. Methods. Data was gathered in an 1997 cross-sectional sample of adolescents (n = 3,859; mean age 14.8 years SD = 1.6) on snacking behavior, bicycle use, demographics, and potential environmental, cognitive and psychological determinants. Data was analyzed using bivariate correlations, multiple linear and binary logistic regression analyses. Results. Less snacking behavior was associated with female gender and a more positive intention, a more positive attitude, and stronger perceived behavioral control towards restricting snacking. Students who used their bicycle for transportation were more likely to attend secondary education, to be native Dutch, to go to school in a less-urbanized city, to be younger, had a more positive intention and perceived stronger behavioral control and subjective norm towards bicycle use. Conclusions. The inclusion of environmental factors increased our understanding of bicycle use for transportation and snacking behavior in adolescents. The environmental factors are suggested to be taken into account in interventions aimed at changing these behaviors in more healthy directions.Clustering of energy balance-related behaviours and their intrapersonal determinantshttp://repub.eur.nl/pub/69774/
Fri, 01 Oct 2004 00:00:01 GMT<div>S.P. Kremers</div><div>G.J. de Bruijn</div><div>H.P. Schaalma</div><div>J. Brug</div>